Field of the Invention
The invention concerns a rotor of a computed tomography (CT) apparatus with a rotatable mechanical support frame for mechanical retention of electrical components and electrical connection elements for electrical connection with electrical components of the computed tomography apparatus, wherein the electrical connection elements are arranged in at least one backplane bus. Furthermore, the invention concerns a rotating unit and a computed tomography apparatus with such a rotor.
Description of the Prior Art
Computed tomography apparatuses are used often for medical imaging,—a primary field of apparatus of the present invention. A computed tomography apparatus essentially has a stationary part and a rotating or rotatable part, and the rotatable part has an acquisition system that includes at least one radiation source and one detector attached to a frame that is mounted such that it can rotate. Such a rotatable frame or rotor has a continuous opening therein for passage of a patient or an examination subject through the rotor, and typically has a stationary support frame and a rotatable support frame for attachment (bolting, for example) of the electrical components of the rotor, in particular of the acquisition system.
In the use of such apparatuses, a very large amount of measurement data must be acquired in a very short time, and must be transmitted to an image reconstruction unit so as to be processed further to reconstruct the desired images. It is furthermore known that, in computed tomography with CT systems having a continuously rotating part, both electrical power and electrical signals must be transmitted between the stationary part and the rotating part of the computed tomography apparatus, and between the different components of the rotating part. Like the x-ray tube and the x-ray detector, the components arranged on the rotatable part, or rotor of the computed tomography apparatus, need an electrical power supply. Large amounts of electrical power are normally transmitted with the use of slip contacts, while electrical signals, as used in data transfer of detector data or time signals and/or control signals, are normally transmitted with the use of no-contact data transfer, for example capacitively or optically. An immense power transfer and an intensive data exchange occur between the stationary part and the rotating part of the gantry of a CT apparatus.
Current computed tomography apparatuses typically have multiple slip rings, in particular for power transmission from the stationary part to the rotating part of the computed tomography apparatus, wherein at least one of the power transmission paths is provided for the radiation source. Numerous electrical connections with cable lines and plug-in elements that are partially attached are already realized at such slip rings. In addition, the different electrical components of the rotor (for example the detector or the radiation source) of such a computed tomography apparatus are typically mounted on (screwed on, for example) the rotating part of the apparatus, wherein the different components are connected among one another or to the respective power supply connections and data connections with conductors (with cables, for example). The cables or the conductors are attached to the rotating part with the use of cable mounts or cable retainers such that the conductors or the cable connections are stable even under the effect of the centrifugal force in the rotating state. For this purpose, among other things the realization of additional anchor points on the rotating part is necessary. For example, additional attachment points are realized by special arrangements of metal layers with special receptacles for the cable retainers, these arrangements being bolted onto the rotating part.
Furthermore, the power transmission—and in general also the signal transmission—between the different components on the rotating part of the computed tomography apparatus is likewise realized in part by plug connections between the respective cables and components. However, in rotating systems this type of connection is only conditionally advantageous due to the centrifugal forces acting on the components and the partial mobility of the cables. At high velocities or given velocity changes, the stability and the longevity of such electrical connections are problematical, particularly given the transmission of large amounts of electrical power. The connections thus must be checked or repaired regularly. Moreover, the cable connections consume a large amount of material (in particular copper), so the total costs are increased. Given each additional component to be attached to the rotating part, the number of cables, the material costs and the weight of the apparatus thus increase. The integration of new components on the rotating part is also complicated due to the cables and cable anchoring devices that are already present. Lastly, the cable connections must be individually mounted and attached, which is complicated. In the event of service, for example for the exchange of a component, first these must be individually demounted and attached again, which increases the work time.